The Arctic, the northernmost polar region characterized by cold winters and vast sheets of white ice, is "undergoing rapid, sometimes turbulent change beyond anything previously experienced," according to a new five-year study.

"While some changes, such as warming temperatures, are gradual, others, such as the collapse of ice sheets, have the potential to be not only abrupt, but also irreversible," says the Arctic Resilience Report. "This means the integrity of Arctic ecosystems is increasingly challenged, with major implications for Arctic communities and for the world as a whole."